Field splinting devices used to support injured limbs or immobilization have been constructed of vinyl, cardboard, foam, air-socks, and nickel-aluminum. Placed against the injured limb, these devices form a support structure to protect the limb during transport to a medical facility. If deemed appropriate by the attending physician, the temporary splint is removed and replaced by a fiberglass cast which is formed in a custom, rigid manner around the injured limb in a clinical setting, usually a physician's office.
Orthopedic casts now commonly used in the treatment of bone breaks and fractures and general limb immobilization are made from fiberglass impregnated with a substance that hardens into a rigid structure. This substance is harder, is waterproof, and more durable than plaster of paris casts, and is radiotranslucent. U.S. Pat. No. 4,411,262 (von Bonin) and U.S. Pat. No. 4,502,479.
Other orthopedic bandages containing other materials generally do not provide the structural strength afforded by fiberglass as dictated by the requirement of having the patient ambulate. However, these bandages do provide some degree of padding for the comfort of the patient.
There are inherent drawbacks to currently available splinting devices and fiberglass casts. Field splinting devices such as cardboard or foam provide only one aspect of limb protection, are not designed to provide a custom fit to the limb, have dimensional limitations, occasionally require additional materials (tape, bandages), and are not considered appropriate devices for after-care protection. Most importantly, they can be difficult to place on the limb due to their rigid structure or application method. This can be of concern as many limb traumas are not easily accessed, and need to be splinted in an angular position.
Although used as the standard of care in post-treatment applications, significant limitations inhibit the fiberglass casting material for use in field applications. Firstly, the entire cast material must be soaked in water and then wrapped circumferentially around the limb, with risk of blood flow restrictions with post-injury swelling. This is often impossible in field situations. Secondly, the splint must be removed and discarded upon arrival to an emergency department or office if a clinician wishes to examine the limb. Thirdly, once in place, the patient can not remove for washing the injured limb. Lastly, once destroyed, a new cast must be formed.